Up to now, digital broadcast services, enabling broadcast services featured by provision of high-quality programs or multi-channel programs, have been implemented as broadcast exploiting a broadcasting satellite (BS) or a communication satellite (CS).
The digital broadcast services are centered about digital high definition television (HDTV). However, in BS digital broadcast services, it has been devised to render services, termed multi-view broadcast, during the time zone other than that for digital high definition television broadcast.
The multi-view broadcast means broadcast services in which the band of the digital high definition television broadcast is split into three channels and plural interrelated contents of a given sole program are broadcast simultaneously as the routine standard definition television (SDTV), as shown in FIG. 1.
For example, when the multi-view broadcast is received, the images from three camera angles of a sports program or a re-broadcast from a theater may be viewed simultaneously, or only images from a desired angle may be viewed.
In viewing the multi-view broadcast, it is necessary to decode the entire digital standard definition television broadcast received by a receiver receiving the multi-view broadcast.
In general, a decoder provided in a receiver receiving the digital broadcast for decoding a received picture stream transiently stores the decoded picture data in a frame memory to output the so stored picture data as a picture frame.
Thus, the decoding in a decoder cannot be performed unless the using state of the frame memory, that is, the void state of the memory area in the frame memory, is verified. If only one picture stream is supplied during the same time interval, it is only sufficient for the frame memory to sequentially output the decoded and stored picture frames to procure the void memory area.
However, in the above-described receiver, for receiving the multi-view broadcast, the use rate of the memory area in the frame memory during a given time interval is increased in keeping with the increase in the number of channels to be decoded during the same time interval, with the result that it becomes difficult to procure the void area in the frame memory and that a problem is raised as to delay in the processing of decoding and as to the increased possibility that the picture frames are not output smoothly. In particular, the delay in the decoding processing is presumed to give rise to adverse effects at the point of switching from the multi-view broadcast to the digital high definition television broadcast.
There is also raised a problem that the frame memory cannot readily be increased in capacity in consideration of cost or difficulties in implementation.